1. Field of the Invention
The present invention relates to a renewable energy extraction device for water or wind applications. The renewable energy extraction device captures a relatively large amounts of flowing water (from ocean, sea, lake, pond, river, stream, ditch, or a canal) or atmospheric air (wind) and increases speed of the captured water or air by decreasing flow cross sectional area in the flow direction. Screen(s) or screening device(s) are used to remove any floating and undesired object from the captured water or air. A relatively small energy extraction component is used to extract energy of the high-speed water or air and convert it to rotational mechanical energy on a rotating shaft (power shaft). A rotation direction control mechanism is used to make the power shaft always rotate in one direction, continuously and without coming to a stop, for situations in which water flow direction may change from time to time. The extracted power is transmitted to an electric generator, pump, compressor, or any other rotary equipment as desired. The captured water or air is finally released to its original source at a downstream location.
2. Description of the Prior Art
Fossil fuels resources are limited and insufficient for the support of long term industrial and technological developments. On the other hand, uncertainties associated with the supply of fossil fuels have had negative impact on global economy for decades. Energy from wind and water has been supplementary to that of fossil fuels. Horizontal-axis wind turbines have been used to convert wind energy into electrical power with practical and industrial applications; however, current horizontal-axis wind turbines are expensive and huge in size. Because of their large sizes, relatively sophisticated facilities are needed for their manufacturing. Moreover, transportation to the location of use, installation, and repair & maintenance of such wind turbines is expensive and requires special equipment and techniques which cannot be afforded by individual customers such as ranchers and farmers. Producing electrical power of industrial and practical importance from water is limited to building hydroelectric power plants, which requires construction of dams over rivers in mountainous areas. Building a dam is time consuming and expensive. Moreover, natural disasters, such earthquakes, can cause damage to dams, thus put the adjacent communities in danger. Water wheels have been used to produce electrical power from rivers, however, at an insignificant rate and with no practical application. Similarly, there is not any industrial, practical, and economical method or device to capture energy from water in oceans or seas at a significant rate.
U.S. Pat. No. 7,969,034 B2 describes a minimal maintenance paddle wheel electric generation device for producing no cost electricity which includes an A-frame base disposed in a fast flowing stream with a paddle wheel mounted between A-frame supports, with the supports resting on the bade, and the paddle wheel including radially arranged dip blades with the rotation of the paddle wheel by the swiftly running water turning a drive gear that engages a series of reduction gears that, in turn, actuate a generator for producing electricity. A pair of paddle wheels can be ganged together on several floating members with the floating members tethered by cables to stanchions fixed on opposed banks of the stream. The paddle wheel can also be supported on buoyant inflatable tubes that have curvilinear members attached to the rear ends for directing water into the channel formed between the tubes thereby enhancing water flow and the angular speed of the paddle wheel for increased power generation.
The paddle wheel electric generation device, described above, is intended only for disposition in a naturally existing hard-flowing stream and is not intended to collect a large amount of flowing water from any stream or river, generate a hard-flowing stream, and capture the energy of the generated hard-flowing stream. In an alternative embodiment, a pair of inflatable tubes have used as the mounting or supporting means for the paddle wheel generation device, with a curvilinear member attached to each Inflatable tube, so that as a portion of water flows between the curvilinear members and the inflatable tubes, water's flow velocity increases thereby striking the dip blades with greater force. As the inflatable tubes, and curvilinear members attached to them, do not cover the entire depth of the water stream, this combination can capture energy only from the surface water, not from all the water flowing in the stream. Moreover, as the entire paddle wheel electric generation device is mounted and supported on two inflatable tubes, indicates that this system can be used only for small paddle wheels thus it cannot be used for large scale power generation. Furthermore, this patent claims only capturing energy of the naturally hard-flowing streams; it does not have a claim to generate a hard-flowing stream before capturing its energy. Finally, this patent does not claim any method to generate a hard-flowing stream before capturing water energy. There is not any screening means to protect the paddle wheel electric generation device against possible floating objects carrying by the stream. Also, there is not any means of shutting down the paddle wheel electric generation device for repair and maintenance periods. It should also be noted that the electrical main or cable of the paddle wheel electric generation device, which is used to connect the generator to the existing electrical grid system, extends outwardly through the main drive shaft. This is in violation of engineering practice and is a serious safety issue as the current carrying cable may come into physical contact with the main drive shaft electrically, thus with all the components of the paddle wheel electric generation device if these components are made from metal.
U.S. Pat. No. 4,868,408 describes a portable water-powered electric generator unit which has a tubular form with opposite open inlet and outlet ends defining a longitudinal flow path for the moving stream water. The tubular form defines a converging venturi terminating at a throat between the inlet and outlet ends. An electric dynamo, having a sealed housing and external driving propeller means, is supported in the flow path downstream of the throat, with the propeller means at the throat. The inlet end is between 2-5 times larger in area than the venturi throat, to speed up the water passing through the propeller means. The tubular form and housing together define a diverging venturi downstream from the throat, decelerating the water with minimal losses before exiting from the open outlet end. The open outlet end is 1.1-1.5 times larger in area than the open inlet end, whereby the slightly faster surrounding stream water blending with the exiting water at the open outlet end may tend to accelerate the exiting water slightly for added efficiencies. A buoyancy chamber, with remotely operated valve and gas pressure means, is on the portable electric generator unit to regulate its overall buoyancy, for adjusting its operative depth of use in the stream.
The portable water-powered electric generator unit, described above, is intended to be a portable device that can be carried by a person, thus it is not for large scale electric power generation. On the other hand, the device needs a source of compressed air and compressor or electricity to operate a control valve which is used to alter depth of the device in water. These features, in addition to routing the control and transmission lines under the water, make the cost of the power that can be generated by a portable device expensive and also necessitate some degree of technical expertise to operate and maintain the device continuously. Moreover, having the dynamo housing and its supporting radial vanes in water flow path have a negative impact on water velocity flowing through the device.
U.S. Pat. No. 4,352,990 describes a water powered electric generator for efficiently converting the power of running water to useful electrical energy; the apparatus including a pair of floating pontoons anchored in a running stream, and between which a plurality of paddle wheels, rotated by the water, drive a gear mechanism connected to an electric generator, and ducts under the pontoons converging toward the paddle wheels, for concentrating more water flow thereto.
The water powered electric generator, described above, uses multiple paddle wheels, with a complicated power transmission mechanism, to generate electricity from water running in a single channel formed between a pair of stationary pontoons. Use of multiple paddle wheels makes the water powered electric generator expensive for the amount of electricity that can be produced. While concentrating flow by narrowing the flow channel has not been included in the claim, it is suggested to narrow the flow channel only by a factor of two; if the water powered electric generator is intended to cover the entire river span, the throat size and the width of each paddle wheel become as half as the river span, making the device an impractical option. Also, endless belts, that are used to transmit power, can transmit a limited power, making the water powered electric generator inappropriate for large scale power generation. On the other hand, in rivers with ordinary water velocities, a single unit with a small narrowing ratio of two cannot produce sufficient electric power even for individual families. Moreover, the water powered electric generator is floating in water, thus it does not take advantage of the total depth of the running water. There is not any screening component, thus objects floating in water can damage paddle wheels and disrupt power generation. When angular ducts are added to the design, they allow escaping of water from the paddle area rather than directing more water into the paddle; this is because flowing water chooses the path with least resistance, thus flows outside the paddle area. As a result, the angular ducts will have a negative impact on function of the device. Therefore, this device is expensive, complicated, cannot function without frequent disruption, and is not appropriate for large scale power generation.
U.S. Pat. No. 4,268,757 describes a water wheel electric generation device as an improved water powered electric generating device which comprises a buoyant platform and a plurality of pylons fixedly mounted in the ocean or riverbed and which slidingly engages the buoyant platform, and a tower means fixedly mounted to the buoyant platform and upwardly extending therefrom. Axle means are rotatable about an axis and pivotedly adapted to the tower means and include means to rotate the axle means in an arc of substantially 120°, connected on one end to the tower means and on the other end to the axle means. The axle means and a plurality of radially and outwardly directed paddle arms are fixedly mounted to the first gear means and formed at the outward end thereof into a paddle to engage the moving water and rotate the first gear means. Pinion gear means toothedly engage the first gear means and are rotated thereby, and generator means are adapted to the pinion gear means and activated thereby to produce electricity.
Structure of the water wheel electric generation device, described above, is impractical for power generation at small scale. On the other hand, the device does not have means of directing large amounts of flowing water towards the paddles; thus magnitude of the generated power can be increased only by increasing the paddle size. Therefore the water wheel electric generation device is not practical and appropriate for power generation at large scale either. Also, the device is not equipped with any means for shutting down for repair and maintenance intervals.
U.S. Pat. No. 4,001,596 describes a wave and current operated power generating device as a pair of hull portions connected in spaced parallel relation supporting a water wheel and forming a passageway there between for driving engagement of flowing water against the vanes of the water wheel. The water wheel is made up of a pair of wheel portions having peripheral gear teeth, and these teeth are engageable with gears which drive electric generators. The vanes of the water wheel are adjustable to vary the driving power thereof and have nozzles thereon arranged to discharge water under pressure to provide a boost for the wheel. A brake is provided to control rotation of the water wheel, and an auxiliary engine is provided to drive the water wheel when necessary. The longitudinal hull portions support a gate mechanism at the inlet end of the water passageway to control the flow of water through such passageway and have air chambers to buoyantly support the device. The device has vertically extendable legs for ground support.
The wave and current operated power generating device, described above, has a complex structure, it is impractical, and is too expensive to be used for power generation at small scale for individual families. Also, while widening water intake is mentioned in description, such feature is not a main focus of the design and is not included in the claims. The device, therefore, lacks means of directing a large amount of water towards the paddle wheel, thus it cannot produce electrical power at large scale with a practical paddle wheel size.
U.S. Pat. No. 3,973,864 describes a wave motor that is comprised of two or more parallel rotors having apertured radial paddle elements with hinged flaps or blades covering the apertures such that upon the impingement of water upon one side of the paddles the blades cover the apertures and the wheel is turned, but upon impingement of water against the other side of the paddles the blades swing open. Each pair of rotors are coaxially mounted and designed for rotation in opposite directions to maximize extracted power regardless of the predominant current direction, and a single take off shaft is coupled to the rotors through a ratchet and gear mechanism.
The wave motor, described above, does not have means of directing large amounts of flowing water towards the rotor; thus magnitude of the generated power can be increased only by increasing the width of the rotor. Therefore the wave motor is not practical and appropriate for power generation at large scale. Also, because of different depths of flow in the two opposite directions, each rotor may be subjected to a different torque. This results in different rotational speeds of rotors. The gear box will not function properly if rotors intend to rotate the single gear at different speeds.
U.S. Pat. No. 7,753,644 describes a vertical axis multi-phased wind turbine power generating system. An adjustable air scoop directs air from a first phase of the prevailing wind into an air turbine for efficient power generation. An exit section, which uses a second phase of the prevailing wind in combination with an optional and adjustable exit section drag curtain or barrier, provides for efficient re-entertainment of this first stage of power generating air back into the downstream prevailing wind. The adjustable air scoop and adjustable exit drag curtain or barrier, where utilized, is automatically rotated in a self correcting manner to be suitably and optimally oriented to the prevailing wind direction. The design provides for a second stage of power generation to be accomplished by additionally utilizing a portion of the second phase of prevailing wind to directly or indirectly drive the turbine in a second stage of power production.
The vertical multi-phased wind turbine system, described above, has a complex design and cannot result in a practical product. The targeted produced power is limited to 50 kW of power, thus it is not intended for large scale power generation. Narrowing air flow path and using a relatively small size turbine have not been listed as claims.
U.S. Pat. No. 5,105,094 describes a method and apparatus for converting wave motion into an alternative energy source. The apparatus comprises a main water pipeline, a water inlet for directing water into the main water pipeline from a plurality of water inlet positions along a path in the direction of wave propagation. A vertical water flow riser is connected to, and receives water from, one end of the main water pipeline. The flow riser includes a cylinder and sealed piston arrangement, the piston movable upwardly in the cylinder responsive to the positive pressure of incoming water beneath the piston, and movable downwardly in the cylinder under the influence of gravity acting on the cylinder and on the water in the cylinder beneath the piston. A drain is provided for allowing a regulated amount of water to drain from the main pipeline on the downward stroke of the piston. The piston is coupled to an energy conversion means for producing an alternate energy output on both the upward and downward strokes of the piston.
For the method and apparatus, described above, a large number of individual water inlets, with their associated piping, should be used to produce energy at a significant rate. This makes the above method and apparatus impractical. Also, collected water from all inlets acts on a single piston to move it upwardly. This is another weakness of the above patent as there is a practical limit on the size of the diameter of the single piston which makes this patent not suitable for energy production at a significant rate. Further, a single drain is used to drain a large amount of water from the system to allow the piston move downwardly. Unless the size of the drain is very large, the downward stroke of the piston will be very slow, which will be a limiting factor on the magnitude of the stroke. Finally, the patent description indicates that the above method and apparatus can be used only in coastal areas.
U.S. Pat. No. 7,862,292 describes a horizontal motion wave power generator which is situated on the ocean shore for converting shore waves to unidirectional rotational force for generating power. By the use of a pair of one-way clutches on a single power shaft the incoming and outgoing motion of ocean waves is converted into continuous unidirectional rotational force to drive an electric generator. The generator system is attached to a base having troughs. The lower portions of the paddle wheels are positioned in the troughs, and engage incoming and outgoing shore waves which rotate the axle of the paddle wheels in a clockwise and counterclockwise direction. The one-way clutches convert the bi-directional rotation of the paddle wheel axle to unidirectional rotation of the power shaft.
The horizontal motion wave power generator, described above, does not collect a large amount of water; the energy that it can produce is limited to the width of the paddle wheels. Therefore, this generator cannot generate power at a significant rate. Also, paddle wheels are fixed to a drive axle which transmits power to the power shaft. The used arrangement, while results in a unidirectional rotation of the power shaft, makes the power shaft to come to a stop each time that wheel's direction of rotation changes. Therefore, the rotational speed of the power shaft oscillates between zero and a maximum value making the horizontal motion wave power generator inefficient in capturing wave energy. Further, the horizontal motion wave power generator is practical only for use in the ocean shore and not for deep water.